Here, a novel aluminum-gallium-phosphate (GAHPO) metal-inorganic framework structure was prepared by hydrothermal method, and it was fully characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, and gravimetric analysis-differential scanning calorimeter (TG-DSC). Single crystal X-ray diffraction results show that GAHPO is attributed to the trigonal system and Rc3 space group. Al(Ga)O6 octahedra and PO4 tetrahedral structures is distorted to form one-dimensional chains, and then is stacked into three-dimensional metal-inorganic frameworks through hydrogen bonding. TG-DSC shows that GAHPO is of high thermal stability, with the initial decomposition temperature of 240 ℃. Compared with aluminum phosphate, the introduction of Ga3+ distorted the AlPO4 lattice, thus weakening and elongating the Al—O bond, which makes more acid catalytic sites exposed and enhanced the catalytic activity. The experiment shows that when the reaction temperature is 60 ℃, and the catalyst dosage is 10% of acetaldehyde, GAHPO could catalyze the condensation of acetaldehyde to produce butanolal with good conversion rate (47%) and excellent selectivity (>99%). The reaction mechanism of acetaldehyde condensation catalyzed by GAHPO was investigated using scavengers, NH3-TPD and specially designed derivatives to confirm the reactive sites of the catalyst and the substrate. This work provides a feasible way for novel aluminum inorganic framework structures and the catalytic applications.